Free calculator · no sign-up
Split car costs fairly
The fairest way to share a car: fuel by distance driven, insurance and car tax in equal shares. Enter how far everyone drove and who paid for what. The result shows right away who pays whom and how much.
Result
How to settle up
- Grandma pays Alex €18.20
- Sam pays Alex €6.97
Per person
| Name | Distance | Paid | Share | Balance |
|---|---|---|---|---|
| Alex | 620 km | €138.50 | €113.33 | +€25.17 |
| Sam | 310 km | €61.20 | €68.17 | −€6.97 |
| Grandma | 70 km | €15.00 | €33.20 | −€18.20 |
Everything is calculated in your browser. Names stay on your device and are not part of the shared link; there everyone is called “Person 1, 2, …”.
Doing this every month? Let the app do it.
In Romy’s Garage you log trips with the odometer and costs as they come up. The balance is always up to date, and “Settle Up” closes the month. You still send each other the money yourselves.
Only the person who adds the car pays: €1.99 per month, with the first month free for eligible Apple IDs. Everyone else rides free.
How the calculator works
Every expense gets a split. By distance means each person pays in proportion to the distance they drove.Equally means everyone pays the same, however much they drove. By share uses a fixed ratio you agree on, such as 2 to 1.
The calculator then compares what each person paid with what they should carry. The difference is their balance. Whoever is behind pays the person furthest ahead until everyone is at zero, which keeps the number of payments as low as possible.
Example with three people
In one month Alex drives 620 km, Sam 310 km and Grandma 70 km, 1,000 km in total. Alex buys fuel for €84.50, Sam for €61.20. Alex also pays the insurance (€54.00) and Grandma the car tax (€15.00).
- Fuel of €145.70 split by distance: Alex carries 62%, Sam 31%, Grandma 7%.
- Fixed costs of €69.00 split equally: €23.00 each.
- Total share: Alex €113.33, Sam €68.17, Grandma €33.20. They paid €138.50, €61.20 and €15.00.
- Result: Grandma pays Alex €18.20, Sam pays Alex €6.97.
Everything is calculated to the cent. If a cent is left over when splitting, it goes to the person with the largest remainder, so the shares always add up to exactly the costs. The app settles up with the same rule.
Which split fits which cost?
By distance
Costs that grow with every mile: fuel, EV charging, tolls, wear and maintenance.
Equally
Costs you pay even when the car stands still: insurance, car tax, cleaning, a fixed parking space.
By share
When you agreed on a fixed ratio, for example because one person uses the car alone during the week.
The calculator’s defaults match the app’s, and you can change them for every expense. There is no right or wrong split. What matters is that everyone knows the rule up front.
Frequently asked questions
How do you split gas fairly when everyone drives different distances?
By distance driven. Whoever drove 600 of 1,000 miles carries 60% of the fuel cost, no matter who paid at the pump. The calculator then offsets what each person has already paid.
How do I know how far everyone drove?
The easiest way is the odometer: read it before and after the trip and enter the difference. In the app that’s “Start Trip” and “End Trip”, with the last odometer reading already filled in.
What if nobody drove?
Then costs split by distance are shared equally too. Otherwise nobody would pay for them.
Can I include depreciation or savings for repairs?
The calculator only splits what you enter. If you want to set money aside for repairs or depreciation, add it as its own cost, for example as “Other” split by distance.
Is this a mileage log for tax purposes?
No. Neither this calculator nor the app is a tax mileage log. They only help you share private costs fairly.
Is my input stored?
No. Everything is calculated in your browser and nothing is sent to a server. A shared result link contains numbers only, no names.
For everyone who shares a car for good
Couples, flatmates, families, colleagues or friends with a holiday car: with private car sharing in Romy’s Garage you log trips and costs on the go and settle up at the end of the month with one tap.
For iPhone and iPad · iOS 17 or later